下面是我写的一段程序，有错误，请高手指教（很简单）
public class PClass
{
private int pNumber;
private double pPrice;
PClass(){}
PClass(int number,double price)
{
pNumber=number;
pPrice=price;

}

public void showNumber()
{
System.out.println(pNumber);
}

public void showPrice()
{
System.out.println(pPrice);
}





public static void main(String[] args)
{
PClass p=new PClass(1,100.0);
p.showNumber();
p.showPrice();
}
}


public class WClass extends PClass
{
private int pStage;
WClass(){}
WClass(int number,double price,int stage)
{
pNumber=number;
pPrice=price;
pStage=stage;
}

public void showStage()
{
System.out.println(pStage);
}


public static void main(String[] args)
{
WClass w=new WClass(1,1000.0,2);
w.showNumber();
w.showPrice();
w.showStage();
}
}


[解决办法]
private的属性只能在类内部访问

改成 public , protected ,或者default 都可以

public int pNumber;
public double pPrice;